Beginner's refractometry (Apogee Technique)

Beginner and pro baristas share tips and tricks for making espresso.
Apogee
Posts: 124
Joined: 8 years ago

#1: Post by Apogee »

Many forum members have reached out with the feeling that refractometry was out of reach of the average home user. I disagree with this.

I wanted to document my espresso life changing experience with the Milwaukee MA871 refractometer because it has worked for me. I know absolutely nothing about the company or its business practices; it is simply the option for cheap, reliable and simple refractometry at home.

There are many ways to learn espresso with hard work; this is my path FWIW. I believe refractometers should be as common as scales in the home barista toolset. This is a compliment to tasting and simply loving the art of espresso. Consistency of technique makes her a far sweeter affair.

Original equipment:
PID Rancilio Miss Silvia (all my love, but I don't miss you)
Rancilio Rocky (Strongly disliked other than price and durability)
Tried for 1 year to learn with this gear and gave up 5 years ago. Made one God shot; ruined my life. Threw both pieces in the dumpster. Remain very happy about that decision.

Current equipment:
Mahlkonig k30
Breville Oracle (for milk steaming, grinder is for decaf drinks for the difficult guest)
Milwaukee MA871
OCD distribution tool
VST 20g ridge less
58.5 sharp edge tamp

First, I want to ask if any posters would appreciate this info before I spend more time? I really don't wish to battle the validity of refractometry; just share my struggles with consistency.

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Hudson
Posts: 163
Joined: 10 years ago

#2: Post by Hudson »

I don't think any of us here would object to hearing more about your experiences. I'm certainly interested in how a refractometer has helped you and how it fits into your workflow!
LMWDP #534

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gr2020
Posts: 358
Joined: 8 years ago

#3: Post by gr2020 replying to Hudson »

Agreed - I'd love to hear more!

Apogee (original poster)
Posts: 124
Joined: 8 years ago

#4: Post by Apogee (original poster) »

Ok. I will do my best to go through the process of developing consistency for me. Everything I will discuss specifically has been tested via refractometry, and the method delivering the higher extraction yield % with greater consistency and speed was kept. 100% of the time this means doing less to get in the way of the coffee.

"Minimum interaction = minimum variation", is my favorite beginner's quote from this web article that really helped me from robdoescoffee:
(https://robdoescoffee.com/2015/11/11/ev ... -espresso/)
For the rest of this topic I define minimum interaction as doing as little as possible to the coffee; and minimum variation as reaching the desired extraction yield % (EY) and strength (TDS) as measured by a refractometer consistently.

Note: there is no golden EY% or TDS, each coffee drinker with each coffee, each day after roast has a different optimum. The key is getting to that pour consistently, and knowing what correction to make if you don't while wasting minimum time and coffee$$$.

Just to avoid messing around, the technique first, every shot I do the following (then I will go through each as I feel like or as requested):

1) Water: Use volvic water or equivalent softness / TDS / etc and don't change it*

2) Machine: Use a ULTRA CLEAN PID controlled machine at 9 bar of pressure with controllable pre-infusion and don't change it*.

I use the Breville Oracle but it doesn't matter. The espresso machine doesn't matter as long as it's temperature and pressure stable and fast enough for you to keep using it as a part of your life. I would take the Breville oracle over a La Marzocco GS3, it's just as consistent and it's faster. (I'm not saying it's better)

3) Temperature: Set temperature to 200 and don't change it*

4) Pre-infusion: Set a long, reduced pressure preinfusion for 7-10 seconds and dont change it*

5) GRIND; THE VARIABLE: Spend more on your grinder than your espresso machine and make sure it's fast enough to fit in your life. I have the Mahlkonig k30 now and can't recommend enough.

Select correct grind size for coffee, drink style and day after roast based on preferred TDS and EY%

THIS IS WHAT YOU CHANGE!!! THIS IS THE ONLY THING YOU CHANGE!!! GRIND SIZE

6) Maintain weight on beans: Use the hopper and don't single dose and don't change it*

7) Grinder cleaning: Use Grindz to clean your grinder of festering oils after every 3 bags of coffee and don't change it*

8) Fresh Coffee: Have fresh roasted coffee delivered each week by a roaster who believes in refractometry. And don't change it*. You can change coffees, but not the quality or freshness.

9) Let beans rest: Wait the correct number of days (3-8 based on bean type, ask roaster) after coffee roast date, use it up befor 10-14 days, ask roaster) and don't change it*

10) Purge stale coffee: Always purge old coffee from your grinder (find retention amount from your grinder manufacturer) before every shot and don't change it*

11) Love scales: Weigh every dose / Weigh every beverage and don't change it*

12) Grinder pre-distribution apogee method: Tilt the portafilter in a circular motion during grinding for distribution of the mound. Simple. Low impact.

Perger's tapping is honestly more effort, talent and practice than I felt like mustering. Besides getting out of the way always worked before. The coffee never tapped me;/

Don't ever touch the coffee or tap the coffee or shake the coffee or stir the coffee; it all makes dead spots that lowers EY% unless one practices it diligently. WDT or blind tumbler works if grinder sucks only. And don't change it*

13) OCD distribution: Use the OCD distribution tool on its deepest setting with a fast, firm spin (will spin freely at the end for another second or so when done firm enough), don't change it*.

14) Tight fitting tamp: Pergtamp or equivalent flat, oversized 58.5+ sharp edge reverse canted (aids in reducing suction on removal) tamp at 30lbs flat and don't ever change it*

15) Tamp removal: Use an ultralight spin polish tamp removal only to break air seal & suction (a true polish is unnecessary) and don't ever change it*

16) Calibrated shower: IMS (appropriate for your machine, they have a tool on website) shower screen, don't change it*. This doesn't matter as much; but its easier to clean and gunk can't get up in the machine as easily.

17) Calibrated basket and dose: Pick a VST ridgeless basket size and matching coffee dose(I use 20 g basket, @ 19.5g dose; this is very machine dependent I believe, On my Breville at 19 g my pucks are mush and at 20 g and above I get more channeling; headroom optimization), test it and don't change it*

18) Bottomless Portafilter: Use a bottomless portafilter and watch every single extraction and don't change it*. It tells you flaws in your technique. An even tiger striped stable center pour means even extraction; without this God shot is unattainable. Work on watching your pours every time; kneel down it's good exercise;) Now give me a couple burpees.

19) THE SHOT!!!: Pull shot to the desired grams for desired time to hit EY and TDS optimum for the coffee and practice until you can nail it every time (FIRST GOAL!!!: 19.5g dose (20g VST, 1:2 brew ratio (dose:beverage grams), 20 EY% , 9.65% TDS = defined average in refractometry) and don't change it*

20) Refractometry: Take a sample using a 3ml plastic pipette and squeeze inside bubble to cool for a quick refractometry TDS measurement (Brix * .85 = TDS, if sample is room temp at test) and don't change it*

21) Daily Shot #2: the learning shot. Always make a minimum of 2 shots per day (within 1-2 hours) as between these 2 shots "coffee differences" is removed as a variable and you can do refractometry based learning very purely for different EY% and TDS% by changing GRIND; the only thing I recommend changing.

Explore ideas for bringing out the flavor of the coffee at its age. Learn to transition from one known god shot to another using only grind and how to move EY% and TDS% to optimize flavor and create your own god shot recipes (fruit, age and gear dependent)

Why learn beginner's refractometry?: Define your personal God-shot via refractometry and hit it consistently by locking every variable but grind.

Apogee (original poster)
Posts: 124
Joined: 8 years ago

#5: Post by Apogee (original poster) »

Why is this list important. It requires no skill, its lightning fast, and delivers fantastically extracted espresso consistently.

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Peppersass
Posts: 3690
Joined: 15 years ago

#6: Post by Peppersass »

A standard Brix meter won't give you accurate TDS measurements for coffee, so your computed extraction yield isn't accurate. See paragraph three on page five of this document:

http://vstapps.com/blog/wp-content/uplo ... meters.pdf

Apogee (original poster)
Posts: 124
Joined: 8 years ago

#7: Post by Apogee (original poster) »

That document is incorrect. I bought the refractometer and filters from VST (who I love btw! Their baskets are worth an easy .5%) and tested both ways. Check out the testing done referencing the Atago refractometer if you need by Socratic I believe. Also please note I keep both machine and sample at room temperature.

I bought both the Milwaukee MA871and the VST and tested for 200 shots with and without VST filters. I like the VST better.

But I sold it for what I paid for it and kept the ugly Milwaukee MA871. It just works for 1/7 the price; she's a mean green machine. Spend the money on the grinder. It's infinitely more important.

Filters don't matter either. They are all consistent and within .5% extraction on average of 200 shots (regardless of device or filter status).

The most important variable actually is the temperature of the sample. Make sure you get it back to near room temp prior to refractometry or it will have you chasing your tail.

I'm tired of this forum making it sound like espresso is a magical art. It isn't any more. There is a shortcut.

Consistent technique & refractometry; only change grind & yield*

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RyanJE
Posts: 1519
Joined: 9 years ago

#8: Post by RyanJE »

Apogee wrote: I'm tired of this forum making it sound like espresso is a magical art. It isn't any more. *
Hey, I am all for affordable methods to improve your skills! But this is a very funny comment...

The workflow and requirements in your "routine" would make me think espresso IS a magical art...
I drink two shots before I drink two shots, then I drink two more....

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aecletec
Posts: 1997
Joined: 13 years ago

#9: Post by aecletec »

RyanJE wrote:The workflow and requirements in your "routine" would make me think espresso IS a magical art...
The magic is in knowing how to do things as desired and just right without ever changing it ;)

Apogee (original poster)
Posts: 124
Joined: 8 years ago

#10: Post by Apogee (original poster) »

Which area sounds magical? I would like to flesh a few of these out and maybe record videos / photos and notes on each step and the why.

Honestly every step is always the simplest, lowest skill and fast choice of what to do, if something has to be done to manage a variable. With everything unnecessary removed or locked in, I can focus on the fruit solely (coffee). Each item was selected because it increased extraction %, sped up my routine while increasing consistency by removing manual skill.

It is very comforting knowing I can extract at any percent I need to bring out the best in a coffee with the lowest skill required. Big change from even a year ago. The only thing I need to do correct is change the grind setting.

Trust me I need the lowest manual skill approach

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